U.S. Ambassador John Roos speaks to journalists after meeting with Japan's Vice Foreign Minister Shuji Kira, unseen, at the foreign ministry in Tokyo on Oct. 17. Okinawan police arrested two U.S. sailors on Tuesday for the alleged rape of a woman. (AP/AP)

Japan lodged a protest with the United States on Wednesday over the alleged rape of a Japanese woman by two U.S. sailors on Okinawa, an island that long has bristled about the heavy American military presence there.

The sailors, identified as Seaman Christopher Browning and Petty Officer 3rd Class Skyler Dozierwalker, both 23, of the Fort Worth Naval Air Station in Texas, were arrested Tuesday.

The woman, in her 20s, was allegedly attacked while walking home early Tuesday. The men had been drinking beforehand, Japanese media reported.

The allegation, described by Japanese Defense Minister Satoshi Morimoto as “very serious,” appears likely to complicate the long-standing efforts by Tokyo and Washington to build a new U.S. Marine base on Okinawa, a step that island residents have fiercely resisted.

With the two sailors in the custody of Okinawan police, a Japanese Foreign Ministry official summoned U.S. Ambassador John V. Roos to a meeting and asked for stricter discipline of American military personnel on the island. The incident recalls the 1995 rape of an Okinawan schoolgirl by three American servicemen, which prompted mass protests and remains a source of bitterness on the southern island.

“I understand — I do understand the anger that many people feel with respect to this reported incident,” Roos said Wednesday in a statement, adding that he shared some of that anger.

The ambassador promised “full and complete and unequivocal cooperation to the Japanese authorities in their investigation of this matter.”

Okinawa hosts many of the almost 50,000 U.S. military personnel stationed in Japan. Washington has tried for years to close the base there and relocate it in a less populated northern area of the island, but Okinawans oppose the construction of any new bases and have blocked those efforts. Some of the islanders’ resentment is also directed at the central government in Tokyo, which they think uses the island as a far-flung dumping ground for American troops.

Okinawans staged a number of protests recently over the deployment of 12 MV-22 Osprey aircraft at a Marine base in the middle of a densely packed city on the island. The hybrid aircraft, which take off like helicopters but fly like planes, have a spotty safety record.

In another meeting Wednesday, Morimoto, the defense minister, told Okinawan Gov. Hirokazu Nakaima that the alleged rape incident is “extremely heinous and despicable,” according to Japan’s Kyodo news agency.

“It hurts the Japan-U.S. security arrangements and the Okinawa people’s trust in the U.S. military,” Morimoto said.